The invention relates generally to material conveying systems, such as to pneumatic partial-vacuum transporting systems, more particularly to the collection and conveying of wastes, such as to the conveying of household wastes. Such systems are presented in publications WO 2009/080880, WO 2009/080881, WO 2009/080882, WO 2009/080883, WO 2009/080884, WO 2009/080885, WO 2009/080886, WO 2009/080887 and WO 2009/080888, among others. The invention also relates to waste feeding means, such as to input points or refuse chutes, with which waste is conveyed, typically by gravity, e.g. from higher input apertures in residential buildings to a lower collection space or corresponding container.
Systems wherein wastes are conveyed in piping by means of a pressure difference or suction are known in the art. In these, wastes are conveyed long distances in the piping by sucking. It is typical to these systems that a partial-vacuum apparatus is used to achieve a pressure difference, in which apparatus negative pressure is brought about in the conveying pipe with partial-vacuum generators, such as with a fan, with vacuum pumps or with an ejector apparatus. A conveying pipe typically comprises at least one valve means, by opening and closing which the replacement air coming into the conveying pipe is regulated. Waste input points, e.g. rubbish containers or refuse chutes, are used in the systems at the waste material input end, into which waste input points material, such as waste material, is fed and from which waste input points the material to be conveyed is conveyed into a conveying pipe by opening a discharge valve means, in which case, by means of the sucking effect achieved by the aid of the partial vacuum acting in the conveying pipe and also by means of the surrounding air pressure acting via the refuse chute, material such as e.g. waste material packed into bags, is conveyed from the refuse chute into the conveying pipe and onwards to a reception point, where the material to be transported is separated from the transporting air and conveyed for further processing or e.g. into a shipping container. The pneumatic waste conveying systems in question can be utilized particularly well in densely populated urban areas. These types of areas have tall buildings, in which the input of wastes into a pneumatic conveying system for wastes is performed via an input point, such as a refuse chute arranged, in the building.
Material can be conducted from an input point along a refuse chute into a container that is lower in the vertical direction, or an intermediate container can be in connection with the input points, into which intermediate container material fed from an input point is initially conducted and from where the waste material is conveyed onwards along the conveying piping to a reception point.
The volume of an intermediate container between the input aperture of a waste input point and the discharge valve typically varies according to the embodiment. Typically the volume can be 100-600 l. An advantage of using an intermediate container is that it can increase the capacity of the input point, in which case the actual conveying system does not need to be started often. Depending on the application site, the conveying system is used 1-3 times a day to convey the material that has collected in the intermediate container. An advantage of a conventional intermediate container is also that the energy consumption of the conveying system can be reduced, because more waste can be conveyed with the same conveying cycle. One drawback, among others, of prior art solutions is that the space requirement of an intermediate container, especially when an input pipe is used as an intermediate container, is large. Typically an input pipe applied in a vertical attitude as an intermediate container becomes long, and a rather deep excavation to install it in the ground must be arranged. The excavation work is expensive, particularly in rocky areas where blasting is required for achieving a trench. The installation depth of a typical intermediate container according to solutions known in the art is in the region of 2.5-3.5 m. The typical installation depth in the installation of the conveying piping of a pneumatic wastes conveying system is smaller than this, in the region of 1-1.5 m.
The aim of the present invention is to achieve a completely new type of solution in connection with the intermediate containers of the input points and conveying pipings of a wastes conveying system, by means of which solution the drawbacks of prior art solutions are avoided. Another aim is to achieve a solution with which the capacity of an intermediate container can be utilized more efficiently than earlier.